Quote (Hanako @ Aug 11 2018 03:10am)
Well scientists seem to agree on the fact that the Universe is flat: "The exact shape is still a matter of debate in physical cosmology, but experimental data from various, independent sources (WMAP, BOOMERanG, and Planck for example) confirm that the observable universe is flat with only a 0.4% margin of error." - Wikipedia, Shape of the universe
So since the Earth is inside the Universe, it has to be flat too (you can't fit a round object into a plane)
You might argue that this is a special case of a sphere (a 2D sphere), but the Earth is actually full (dig a bit in your backyard and you'll notice it), so I'd rather call it a 2D ball or a disk actually, neglecting asperities...
Following your logic, your head is flat.